Method of making slide fasteners



Oct. 5, 1937.. H. w. BROWNSDON METHOD OF MAKING SLIDE FASTENERS OriginalFiled Oct. 15, 1932 .m. mm mm w W m By W 5% A TTORNEYS.

Patented Oct. 1 937 assignor to Hookless Fastener Company, a corporationof Pennsylvania Original application October 15, 1932, Serial No.637,984, now Patent No. 1,920,138, dated July 25, 1933. Divided andthisapplicatlon July 21, 1933, Serial No. 681,529.v In Great BritainOctober 17, 1931 a This invention relates to separable interlockingfasteners in which two rows of fastener members are attached to a pairof tapes and so constructed that the elements of one row interlock withthose 5 of the other row. The fastener members may assume various forms,the form used in illustrating-this invention being that of a well knownslide fastener in which the two rows of fastener elements areinterlocking and separated by a slider. Y

This application is a division of the application, Ser. No. 637,984,filed October 15, 1932, jointly with George H. C. Corner, now Patent No.1,920,138.

It is among the objects of this invention to provide a strong andimproved bond between non-metallic fastener members and their supportingstrips or tapes. More specifically it is one of my objects to provide afastener in which 20 there is an integral bond between the fastenermembers and the supporting strips or tapes.

One of the features of the invention consists in forming an intimatejoint between each individual interlocking element and a supporting 5strip, for example, a homogeneous, autogenous,

' or physico-chemical bond between the interlocking element and materialconstituting or included in the strip.

Other objects and advantages of the invention 30 will be apparent fromthe accompanying description and drawing, in which: I

Fig. 1 is aperspective viewof a complete fastener stringer embodying theinvention, Fig. 2 is a cross-section'of a tape at one stage 35 of themanufacture of a fastener in accordance with one embodiment of myinvention, the proportions of some elements being exaggerated forclearness, and a Fig. 3 is an enlarged perspective view of a tape afterbeing prepared, as indicated in Fig. 2, for the attachment of theinterlocking elements.

' In Fig.v 1, Iii represents a flexible supporting.

' member, preferably in-the formof a fabric .tape, to the edge ofwhich'are secured in uniformly 45 spaced relation a number ofinterlocking elements, exemplified as including an interlockingh'ead'portion l2 projecting from the edge of the tape and a supportingbase portionbifurcated to provide two legs it which straddle the tape'50 and are secured to it.

In accordance with the present invention the interlocking elements areformed of nonmetallic material, examples of which are cellulose ester orether materials, such a pyroxylln or nitro-cellu- 55 lose; syntheticresins, such as resinous polymerized unsaturated organic compounds,phenolaldehyde resins, ureaor thiourea-aldehyde resins,polyhydric-alcohol-polybasic acid resins; and compressed and/orimpregnated fiber.

,For the sake of illustration, we may consider that the interlockingelements are formed of cellulose benzyl ether molding powder. A thinstrip of plasticized cellulose benzyl ether which has been softened byheat or by soaking in a solvent, is applied to one or both faces of afabric strip along one edge. In Fig. 2 the fabric strip I0 is placedbetween the bonding strips I6 of softened cellulose benzyl ether andpressed between two rollers l8. This operation rolls the strips it intothe interstices of the fabric and forms an intimate attachmentbetweenthe two, resulting in a perfectly flexible fabric base impregnated withthe cellulose benzyl ether to form an adhesive or bonding edge, as shownin Fig. 3. The completely formed interlocking elements in this instancemade of cellulose benzyl ether, are then placed along the tape as shownin Fig. 1, in the desired closely and uniformly spaced relation andattached to the tape. Conveniently the interlocking elements may beapplied while the strips l8 are still soft from the rolling operationbutpreferably the strips l6 and the jaws Mare softened for this step inthe process. When the solvent evaporates, the stickiness of the materialdisappears and the interlocking elements are integrally united to thestrips it which previously have been pressed into the interstices of thefabric tape. The supporting tape thus contains an intimately and firmlyattached root or support,

intermingled with the flbers of the fabric, which support has becomeintegral with the material of the interlocking elements. Likewise theinterlocking elements are homogeneously united to the bearing elementsit. However, the strips it do not impair the flexibility of the tape. 7

The term bonding material as used herein and in the appended claimsmeans a material in the plastics class which under ordinary conditionsof temperature and pressure is hard and which is capable of beingsoftened by the action of heat or solvent. The term impregnated: as usedin conjunction with bonding material" means forced into the intersticesof the fabric or equivalent porous support by the action of pressurewhile the material is in a soft or semi-soft condition and is intendedto distinguish from the mere common application of liquid or semi-liquidcement.

The interlocking elements may also be applied first and softened afterapplication. This softening may be accomplished by heat, or the tape maybe saturated either with a suitable solvent alone, or with a solution ofthe material of which the elements are formed. This acts to soften theinner faces of the applied prongs.

While I have shown and described in this application one embodimentwhich my invention may assume in practice, it will be understood thatthis embodiment is merely for the purpose of illustration anddescription and that various other forms may be devised within the scopeof my invention as defined in the following claims.

What I claim as my invention is:

l. The method of making separable interlocking fasteners of the typehaving fastener elements uniformly spaced along the edge of a fabricsupport, which consists in applying bonding material continuously alongthe supporting edge under sufllcient presure to cause said material toimpregnate the fabric, arranging a series of fastener elements atuniformly spaced intervals on said bonding material, and uniting thesame thereto by temporarily softening the material of the contactingsurfaces suillciently to cause them to adhere together.

2. The method of making separable interlocking fasteners of the typehaving fastener elements secured to a fabric support at uniformly spacedintervals, which consists in applying thin strips of bonding material tothe supporting edge while in a semi-plastic condition and withsufficient pressure to cause said bonding material to impregnate thefabric, said bonding material being soluble, and arranging fastenerelements made of a material soluble in the same solvent as said bondingstrips at uniformly spaced intervals along the supporting edge, andthereafter softening the surfaces of said bonding material and afastener elements by solvent sufficiently to cause them to adheretogether.

